Side impact sensor systems

ABSTRACT

A vehicle including a side impact crash sensor, a transfer structure interposed between the side of the vehicle and the sensor and an occupant restraint system such as a side impact airbag system. When an object strikes the side of the vehicle or vice versa, the transfer structure serves to transfer the lateral force from the side of the vehicle to the sensor and is designed so that it does not distort upon the application of the lateral force. The side impact crash sensor detects the force or acceleration applied to the side of the vehicle, and the airbag system connected to the sensor deploys an airbag based on the detected force or acceleration. The transfer structure may be constructed to account for mismatch between the point of impact of an object on the side of the vehicle and the location of the sensor.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent applicationSer. No. 09/435,045 filed Nov. 8, 1999 which is a continuation-in-partof U.S. patent application Ser. No. 09/114,962 filed Jul. 14, 1998, nowU.S. Pat. No. 6,419,265 which is a continuation-in-part of U.S. patentapplication Serial No. 08/101,017 filed Sep. 16, 1993, now U.S. Pat. No.5,842,716, all of which are included herein by reference.

FIELD OF THE INVENTION

[0002] This invention relates to side impact crash sensors for vehiclesand side impact airbag systems.

BACKGROUND OF THE INVENTION

[0003] Self-contained airbag systems contain all of the parts of theairbag system within a single package, in the case of mechanicalimplementations, and in the case of electrical or electronic systems,all parts except the primary source of electrical power and, in somecases, the diagnostic system. This includes the sensor, inflator andairbag. Potentially these systems have significant cost and reliabilityadvantages over conventional systems where the sensor(s), diagnostic andbackup power supply are mounted separate from the airbag module. Inmechanical implementations in particular, all of the wiring, thediagnostic system and backup power supply are eliminated. In spite ofthese advantages, self-contained airbag systems have only achievedlimited acceptance for frontal impacts and have so far not beenconsidered for side impacts.

[0004] The “all-mechanical” self-contained systems were the first toappear on the market for frontal impacts but have not been widelyadopted partially due to their sensitivity to accelerations in thevertical and lateral directions. These cross-axis accelerations havebeen shown to seriously degrade the performance of the most common allmechanical design that is disclosed in Thuen, U.S. Pat. No. 4,580,810.Both frontal and side impact crashes frequently have severe cross-axisaccelerations.

[0005] Additionally, all-mechanical self contained airbag systems, suchas disclosed in the Thuen patent, require that the sensor be placedinside of the inflator which increases the strength requirements of theinflator walls and thus increases the size and weight of the system. Onesolution to this problem appears in Breed, U.S. Pat. No. 4,711,466, buthas not been implemented. This patent discloses a method of initiatingan inflator through the use of a percussion primer in combination with astab primer and the placement of the sensor outside of the inflator. Onedisadvantage of this system is that a hole must still be placed in theinflator wall to accommodate the percussion primer that has its ownhousing. This hole weakens the wall of the inflator and also provides apotential path for gas to escape.

[0006] Another disadvantage in the Thuen system that makes it unusablefor side impacts, is that the arming system is sealed from theenvironment by an O-ring. This sealing method may perform satisfactorilywhen the module is mounted in the protected passenger compartment but itwould not be satisfactory for side impact cases where the module wouldbe mounted in the vehicle door where it can be subjected to water, salt,dirt, and other harsh environments.

[0007] Self-contained electrical systems have also not been widely used.When airbags are used for both the driver and the passenger,self-contained airbag systems require a separate sensor and diagnosticfor each module. In contrast to mechanical systems the electronic sensorand diagnostic systems used by most vehicle manufacturers are expensive.This duplication and associated cost required for electrical systemseliminates some of the advantages of the self contained system.

[0008] Sensors located in the passenger compartment of a vehicle cancatch most airbag-required crashes for frontal impacts, particularly ifthe occupants are wearing seatbelts. However, researchers now believethat there are a significant number of crashes which cannot be sensed intime in the passenger compartment and that this will require theaddition of another sensor mounted in the crush zone (see, for example,Breed, D. S., Sanders, W. T. and Castelli, V. “A Critique of SinglePoint Sensing”, Society of Automotive Engineers Paper No. 920124). Iftrue, this will eventually eliminate the use of self-contained airbagsystems for frontal impacts.

[0009] Some of these problems do not apply to side impacts mainlybecause side impact sensors must trigger in a very few milliseconds whenthere is no significant signal at any point in the vehicle except wherethe car is crushing or at locations rigidly attached to this crush zone.Each airbag system must be mounted in the crush zone and generally willhave its own sensor. Self contained airbag systems have heretofore notbeen used for occupant protection for side impacts which is largely dueto the misconception that side impact sensing requires the use ofelongated switches as is discussed in detail in U.S. Pat. No. 5,231,253,incorporated by reference herein. These elongated prior art side impactcrush-sensing switches are not readily adaptable to the more compactself-contained designs. The realization that a moving mass sensor wasthe proper method for sensing side impacts has now led to thedevelopment of the side impact self contained airbag system of thisinvention. The theory of sensing side impacts is included in the '253patent referenced above.

[0010] In electromechanical and electronic self-contained modules, thebackup power supply and diagnostic system are frequently mounted apartfrom the airbag system. If a wire is severed during a crash but beforethe airbag deploys, the system may lose its power and fail to deploy.This is more likely to happen in a side impact where the wires musttravel inside of the door. For this reason, mechanical self-containedsystems have a significant reliability advantage over conventionalelectrical systems.

[0011] Finally, the space available for the mounting of airbag systemsin the doors of vehicles is frequently severely limited making itdesirable that the airbag module be as small as possible. Conventionalgas generators use sodium azide as the gas generating propellant. Thisrequires that the gas be cooled and extensively filtered to remove thesodium oxide, a toxic product of combustion. This is because the gas inexhausted into the passenger compartment where it can burn an occupantand is inhaled. If the gas is not permitted to enter the passengercompartment, the temperature of the gas can be higher and the productsof combustion can contain toxic chemicals, such as carbon dioxide.

[0012] These and other problems associated with self-contained airbagsystems and side impact sensors are solved by the invention disclosedherein.

OBJECTS AND SUMMARY OF THE INVENTION

[0013] This invention is primarily concerned with a novel self-containedairbag system for protecting occupants in side impacts. It is alsoconcerned with the sensors used either with self-contained modules orapart from the airbag module. This is accomplished by using the sensorsdescribed in U.S. Pat. No. 5,231,253 referenced above, along with otherimprovements described in detail below. This invention is secondarilyconcerned with applying some of the features of the novel side impactsystem to solving some of the problems of prior art mechanical airbagsystems discussed above.

[0014] The sensitivity to cross axis accelerations of current allmechanical airbag systems, for example, is solved in the presentinvention, as discussed in U.S. Pat. No. 5,233,141, incorporated byreference herein, through the substitution of a hinged sensing elementfor the ball sensing mass in the Thuen patent.

[0015] The problems resulting from the hole in the inflator wall when apercussion primer is used as in Breed, U.S. Pat. No. 4,711,466, aresolved in the present invention through the placement of sensitivepyrotechnic material in a cavity adjacent to the outside wall of theinflator and then using shock from a stab primer to initiate thepyrotechnic material and thus the inflator. An alternate solution, asdiscussed below, is to make the size of the hole created in the inflatorby the action of the stab primer small so that the total quantity of gaswhich escapes into the sensor is small compared with the quantity of gasused to inflate the airbag.

[0016] Finally, in the self-contained airbag system disclosed herein,provision is made to exhaust the gas outside of the passengercompartment, into the vehicle doors, or other side areas of the vehicle.This permits the use of higher gas temperatures and alternate propellantformulations, such as nitro-cellulose, which produce toxic combustionproducts. Both of these changes reduce the size, weight and cost of thesystem.

[0017] Briefly, the self-contained airbag system of this inventionconsists of a sensor having a movable sensing mass, means to sense theposition of the sensing mass to determine if the airbag should bedeployed, a sealed housing, a gas generator for producing the gas toinflate the airbag, an airbag, and mounting hardware.

[0018] The sensors used here are either electronic, electromechanical ormechanical but all have a movable mass where the motion of the mass issensed either electronically or mechanically.

[0019] Principal objects and advantages of this invention are:

[0020] 1. To provide a self contained side impact occupant protectionairbag system incorporating the advantages of a movable mass sensorresulting in a low cost, compact airbag system.

[0021] 2. To provide a frontal impact all mechanical airbag systemincorporating a hinged sensing mass to eliminate the effects ofcross-axis accelerations on the operation of the sensor.

[0022] 3. To provide a method of minimizing the leakage of the inflatorgases out of the inflator portion of a self contained airbag system intothe sensor portion and the associated problems.

[0023] 4. To provide a side impact airbag system which utilizes thecrush of the vehicle side to arm the sensor and motion of a sensing massto initiate deployment.

[0024] 5. To provide a method of hermetically sealing a self containedairbag system while permitting an external force to be used to arm thesystem.

[0025] 6. To provide a more compact self contained side impact airbagsystem by providing for the exhausting of the airbag gas into thevehicle door or side, therefore permitting the use of higher temperaturegas and propellants which would otherwise not be viable due to theirtoxic products.

[0026] 7. To provide an all-mechanical airbag system utilizing acantilevered firing pin spring which also provides the biasing force onthe sensing mass thereby providing a simplified design.

[0027] 8. To provide an all-mechanical airbag system with a thin sensormounted outside of the inflator housing but in line with it to reducethe size of the system and permit the use of conventional inflatordesigns.

[0028] 9. To provide a highly reliable side impact occupant protectionelectromechanical self-contained airbag system.

[0029] 10. To provide a highly reliable side impact occupant protectionelectronic self contained airbag system.

[0030] 11. To provide a method of obtaining the power for an electricalself contained airbag system from other components within the doorthereby minimizing the requirement for separate wiring for the airbagsystem.

[0031] 12. To provide a power supply within the self contained moduleand a simplified diagnostic system for an electrical self containedairbag system.

[0032] 13. To provide a self contained airbag system design that permitsthe arming of the sensor after it has been mounted onto the vehicle butbefore the inflator is mounted to provide greater safety againstunwanted deployments.

[0033] 14. To provide an electronic, electromechanical or mechanicalsensor for use with either a self-contained airbag system orconventional airbag system wherein the sensor system senses theacceleration of the vehicle member on which it is mounted and where inthe sensed acceleration is the crush zone acceleration and is used tocontrol the deployment of the side airbag.

[0034] Other objects and advantages will become apparent from thediscussion below.

[0035] In order to achieve at least some of the objects noted above, oneembodiment of the vehicle includes a side impact crash sensor, atransfer structure interposed between the side of the vehicle and thesensor, and an occupant restraint device such as a side impact airbagsystem. When an object strikes the side of the vehicle, the transferstructure transfers the lateral force from the side of the vehicle tothe sensor. The side impact crash sensor detects the lateral force oracceleration applied to a side of the vehicle. The airbag system isconnected to the sensor and arranged to deploy based on the force oracceleration detected by the sensor. The transfer structure may be aplate, and is optionally arranged to adjust for a mismatch between thepoint of impact of an object on the side of the vehicle and the sensor.The plate may be mounted on a main structural beam in the vehicle, suchas the main structural beam of the door of the vehicle. The entiresystem may be mounted between the inner and outer panels of the door ofthe vehicle. In another embodiment, there is a mismatch adjustmentstructure in place of or in combination with the transfer structure.

[0036] The side impact crash sensor for a vehicle may include a housing,a mass within the housing movable relative to the housing in response toaccelerations of the housing, means responsive to the motion of the massupon acceleration of the housing in excess of a predetermined thresholdvalue for controlling an occupant protection apparatus and means formounting the housing in such a position and a direction as to sense animpact into a side of the vehicle. The sensor may be an electronicsensor arranged to generate a signal representative of the movement ofthe mass and optionally comprise a micro-processor and an algorithm fordetermining whether the movement over time of the mass as processed bythe algorithm results in a calculated value which is in excess of thethreshold value based on the signal. In the alternative, the mass mayconstitute part of an accelerometer, i.e., a micro-machined accelerationsensing mass. The accelerometer could include a piezo-electric elementfor generating a signal representative of the movement of the mass.

[0037] With respect to the arrangement of the sensor, some non-limitingmounting locations include inside a door of the vehicle, between innerand outer panels not associated with a door of the vehicle, a seat inthe vehicle and remote from the side of the vehicle in which case, thevehicle should include a sufficiently strong member connecting thesensor to the vehicle side such that there is little or no plasticdeformation between the sensor and the side of the vehicle.

[0038] Another embodiment of the sensor comprises a sensor assemblyresponsive to a side impact for controlling the occupant protectionapparatus, i.e., the airbag(s). The sensor assembly comprises a sensorhousing, a mass arranged within the sensor housing and movable relativeto the housing in response to acceleration thereof and means responsiveto the movement of the mass upon acceleration of the housing in excessof a predetermined threshold value for controlling deployment of theairbag(s). The assembly may be mounted onto a side door of the vehicleand/or a side of the vehicle between the centers of the front and rearwheels of the vehicle in such a position and a direction as to causemovement of the mass upon an impact into the side of the vehicle.Additional mounting possibilities include in contact with a side doorassembly of the vehicle and/or a side panel assembly of the vehiclebetween the centers of the front and rear wheels in such a position anda direction as to cause movement of the mass upon an impact into theside of the vehicle.

[0039] One embodiment of a side impact airbag system for a vehicle inaccordance with the invention comprises an airbag housing defining aninterior space, one or more inflatable airbags arranged in the interiorspace of the system housing such that when inflating, the airbag(s)is/are expelled from the airbag housing into the passenger compartment(along the side of the passenger compartment), and inflator means forinflating the airbag(s). The inflator means usually comprise an inflatorhousing containing propellant. The airbag system also includes a crashsensor as described above for controlling inflation of the airbag(s) viathe inflator means upon a determination of a crash requiring inflationthereof, e.g., a crash into the side of the vehicle along which theairbag(s) is/are situated. The crash sensor may thus comprise a sensorhousing arranged within the airbag housing, external of the airbaghousing, proximate to the airbag housing and/or mounted on the airbaghousing, and a sensing mass arranged in the sensor housing to moverelative to the sensor housing in response to accelerations of thesensor housing resulting from, e.g., the crash into the side of thevehicle. Upon movement of the sensing mass in excess of a thresholdvalue, the crash sensor controls the inflator means to inflate theairbag(s). The threshold value may be the maximum motion of the sensingmass required to determine that a crash requiring deployment of theairbag(s) is taking place.

[0040] The crash sensor of this embodiment, or as a separate sensor ofanother embodiment, may be an electronic sensor and the movement of thesensing mass is monitored. The electronic sensor generates a signalrepresentative of the movement of the sensing mass that may be monitoredand recorded over time. The electronic sensor may also include amicroprocessor and an algorithm for determining whether the movementover time of the sensing mass as processed by the algorithm results in acalculated value that is in excess of the threshold value based on thesignal.

[0041] In some embodiments, the crash sensor also includes anaccelerometer, the sensing mass constituting part of the accelerometer.For example, the sensing mass may be a micro-machined accelerationsensing mass, in which case, the electronic sensor includes amicro-processor for determining whether the movement of the sensing massover time results in an algorithmic determined value which is in excessof the threshold value based on the signal. In the alternative, theaccelerometer includes a piezo-electric element for generating a signalrepresentative of the movement of the sensing mass, in which case, theelectronic sensor includes a micro-processor for determining whether themovement of the sensing mass over time results in an algorithmicdetermined value which is in excess of the threshold value based on thesignal.

[0042] The inflator means may be any component or combination ofcomponents which is designed to inflate an airbag, preferably bydirecting gas into an interior of the airbag. One embodiment of theinflator means may comprise a primer. In this case, the crash sensorincludes an electronic circuit including the accelerometer and theprimer such that upon movement over time of the sensing mass results ina calculated value in excess of the threshold value, the electroniccircuit is completed thereby causing ignition of the primer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The invention will be described with reference to the followingnon-limiting drawings in which:

[0044]FIG. 1 is a perspective view with certain parts removed of an allmechanical self contained airbag system for mounting on the side of avehicle to protect occupants in side impacts,

[0045]FIG. 2 is a cross sectional view of the apparatus of FIG. 1 takenalong line 2-2;

[0046]FIG. 3 is an enlarged fragmentary view of the sensing mass andattached lever arm extending from the D-shaft prior to rotation of thesensing mass incident to a crash as adapted to the all mechanical systemof U.S. Pat. No. 4,580,810;

[0047]FIG. 4 is a similar view as FIG. 3 showing the sensing massrotated as a result of a crash;

[0048]FIG. 5 is a view of the apparatus shown in FIG. 4 taken along line5-5 and rotated 90 degrees to the right;

[0049]FIG. 6 is a cross section view of a sensor for use in an allmechanical system where the sensor is mounted outside of the inflatorhousing, shown in an unarmed or safe position prior to assembly with aninflator;

[0050]FIG. 7 is a cross section view of the sensor of FIG. 6 shownmounted on an inflator, shown in a fragmentary view, after it hastriggered in response to a vehicle crash;

[0051]FIG. 8 is a cross section view of a through bulkhead initiationsystem adapted to a mechanical self contained airbag system;

[0052]FIG. 9 is a perspective view of a mechanical self contained airbagsystem using a crush sensing arming system, shown in the state before acrash occurs;

[0053]FIG. 9A is a blowup with certain parts removed showing a portionof the sensor shown in FIG. 9 in the unarmed position;

[0054]FIG. 10 is a cross section view of the apparatus of FIG. 9 takenalong line 10-10 showing the crush sensing arming system after it hasbeen activated by vehicle crush but before the sensing mass of thediscriminating sensor has begun to move;

[0055]FIG. 10A is a blowup with certain parts removed showing a portionof the sensor shown in FIG. 10 in the armed position;

[0056]FIG. 11 is a cross section view of the apparatus of FIG. 9, alsotaken along line 10-10, showing the crush sensing arming system after ithas been activated by vehicle crush and showing the sensing mass of thediscriminating sensor after it has moved and released the firing pin,triggering the inflation of the airbag;

[0057]FIG. 11A is a blowup with certain parts removed showing portion ofthe sensor shown in FIG. 11 in the fired position;

[0058]FIG. 12 is a perspective view of a side impact airbag systemillustrating the placement of the airbag vents in the door panel and theexhausting of the inflator gases into the vehicle door and also showingthe use of a pusher plate to adjust for the mismatch between the pointof impact of an intruding vehicle and the sensor of a self containedside impact airbag system;

[0059]FIG. 13 is a cross section view of a self-contained side impactairbag system using an electromechanical sensor;

[0060]FIG. 14 is a cross section view of a self-contained side impactairbag system using an electronic sensor;

[0061]FIG. 15 is a schematic of the electric circuit of anelectromechanical or electronic self contained side impact airbagsystem; and

[0062]FIG. 16 is a side view of a vehicle showing the preferred mountingof two self contained airbag modules into the side of a coupe vehicle,one inside of the door for the driver and the other between the innerand outer side panels for the rear seat passenger.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] Referring to the accompanying drawings wherein like referencenumerals refer to the same or similar elements, FIGS. 1 and 2 show anall-mechanical self-contained airbag system for mounting on the side ofa vehicle to protect occupants in side impacts in accordance with theinvention which is designated generally as 100. The airbag system 100contains one or more inflatable airbags 110, an inflator assembly 120, amounting plate 160 for mounting the airbag system 100 on the side of thevehicle and a sensor assembly 140 mounted to the inflator assembly 120.The sensor assembly 140 contains a rotatable, substantially planarsensing mass 141 and a cantilevered biasing spring 142 which performsthe dual purposes of biasing the sensing mass 141 toward its at restposition shown in FIG. 2 and also providing the energy to the firing pin143 required to initiate a stab primer 122 as further described below.The sensing mass 141 contains a firing pin spring-retaining portion 144that restrains the firing pin 143 during the sensing time and releasesit when the sensing mass 141 has rotated through the sensing angle. Theretaining portion 144 is an L-shaped descending part formed on a planarsurface of the sensing mass 141 and defines a cavity for retaining anend of the spring 142.

[0064] As shown in FIG. 1, the mounting plate 160 constitutes a housingfor the airbag system 100, i.e., it has a bottom wall and flanged sidewalls extending from edges of the bottom wall which define an interiorspace in which the airbag(s) 110 and a portion of the inflator assembly120 are arranged. The bottom wall is substantially flat and has asubstantially circular aperture. The inflator assembly 120 is positionedin the aperture so that a portion thereof extends on either side of thebottom wall (See FIG. 2). Also as shown in FIG. 2, the housing of theinflator assembly 120 includes a flange that abuts against the bottomwall of mounting plate 160 around the aperture. As will be appreciatedby those skilled in the art, the flanged side walls of the mountingplate 160 are positioned around a panel on the side of the vehicle,e.g., a blow-out panel in the side door, so that the airbag(s) 110 wheninflating will be expelled from the interior space defined by themounting plate 160 into the passenger compartment of the vehicle. Themounting plate 160 may thus be mounted to a frame of the side door byattaching the flanged side walls to the frame or attaching anotherportion of the mounting plate to the frame. The actual manner in whichthe mounting plate 160 is mounted in the side door, or on the side ofthe vehicle, is not critical so long as the mounting plate 160 ispositioned to allow the airbag(s) 110 to be expelled from the interiorspace into the passenger compartment. Mounted as such, the sensorassembly 140 will be most proximate the exterior of the vehicle with theairbag 110 most proximate the passenger compartment of the vehicle.

[0065] The sensing mass 141 is connected to the housing 101 of sensorassembly 140 through a hinge 145 at one end whereby the opposed end isunrestrained so that the sensing mass 141 rotates about the hinge 145.In view of the mounting of the airbag system 100 on the side of thevehicle, hinge 145 defines a rotation axis which is perpendicular to thelongitudinal direction of travel of the vehicle (x) as well asperpendicular to a direction (y) transverse to the longitudinaldirection of travel of the vehicle, i.e., it is a vertical axis (z).

[0066] The sensor housing 101 includes opposed housing wall portions 146and 148, a top cover 150 and a bottom cover 151 which is connected to,mounted on or the same part as a top cover 121 of the inflator assembly120. The sensor housing 101 is filled with air and sealed (whenappropriately mounted to the inflator assembly 120 whereby a smallorifice 127 in bottom cover 151 is closed by the inflator assembly 120)so as to maintain a constant air density regardless of the ambienttemperature or pressure. The sensor housing walls 146,148 and sensingmass 141 are preferably molded along with the hinge 145 in a singleinsert molding operation to provide a careful control of the dimensionsof the parts and particularly of a clearance 152 between the walls146,148 and the sensing mass 141 for the reasons described below.

[0067] The inflator assembly 120 comprises a stab primer 122, ignitermix 130 associated with the stab primer 122, one or more propellantchambers 123 containing propellant 124 and a series of cooling andfiltering screens 125. In the particular design shown in FIGS. 1 and 2,the stab primer 122 has been placed inside of an igniter housing portion126 of the housing of the inflator assembly 120, the housing of theinflator assembly being formed by opposed housing sections 121 and 129.Housing sections 121 and 129 cooperate to define a substantiallycylindrical housing for the inflator assembly 120. Housing section 121is coupled to the sensor housing 101. Exit orifices 128 are provided inthe housing section 129 to allow the gas generated by the burningpropellant 124 to flow into the airbag 110 to inflate the same. A smallorifice 127 has been left open in the bottom cover 151 of the housing101 of the sensor assembly 140, as well as the housing section 121, toallow the firing pin 143 to enter into the interior of the inflatorassembly 120 and cause initiation of the stab primer 122. The stabprimer 122 is from a family of the most sensitive stab primers requiringless than 25 in-oz of energy for activation. The standard M55 militarydetonator is a member of this class and has been manufactured in verylarge quantities during war time. For the purposes of this disclosure,the term primer will be used to represent both primers and detonators.The small orifice 127 will permit some gas to enter the sensor housing101 during the time that the propellant 124 is burning and inflating theairbag 110 but since its area is less than 1% of the area of the exitorifices 128 through which the generated gas enters the airbag 110, lessthan 5% of the generated gas will pass into the sensor. Naturally, alarger orifice could be used but in all cases the amount of gas whichpasses into the sensor housing 101 will be less than 10% of the totalgas generated. Since this gas will be hot, however, it will destroy thesensor assembly 140 and leak into the door. In another implementationdiscussed below, a through bulkhead initiation system is used to preventany gas from passing into the sensor assembly from the inflatorassembly.

[0068] During operation of the device, sensing mass 141 rotates relativeto sensor housing 101 in the direction of the arrow (shown in FIG. 2)under the influence of the acceleration with its motion being retardedby the biasing spring 142 and the gas pressure forces. Upon a sufficientrotation, biasing spring 142 is released from the retaining portion 144of the sensing mass 141 and moves toward the inflator assembly 120 andthe firing pin 143 formed in connection with the biasing spring 142moves to impact stab primer 122 which burns and ignites the igniter mix130. The igniter mix, which is typically composed of boron and potassiumnitrate, then ignites the propellant 124 that burns and generates gas.The gas then flows through exit orifices 128 into the inflatable bag110, inflating the bag.

[0069] In the embodiment shown in FIGS. 1 and 2, the stab primer 122 hasbeen located in the center of the inflator housing. This is theconventional location for electrical primers in most driver's sideinflator designs. The sensor is placed adjacent and in line with theinflator permitting the use of conventional inflator designs whichminimize the size, complexity and weight of the inflator. The sensingmass 141 is approximately of square shape and the sensor housing 101 ismade circular to mate with the inflator design.

[0070] In the particular design shown in FIGS. 1 and 2, a burningpropellant inflator design was illustrated. Naturally, other propellanttechnologies such as a stored gas or hybrid (a combination of stored gasand propellant) could have been used without departing from theteachings of this invention.

[0071] It will be appreciated by those skilled in the art that since theairbag system 100 is designed to activate in side impacts, the sensingmass 141 is arranged for movement in a direction perpendicular to thesides of the vehicle, i.e., perpendicular to the longitudinal directionof travel of the vehicle, or in a pivoting movement about a verticalpivot axis. In this manner, the acceleration of the sensor housing 101inward into the passenger compartment (that is, acceleration in alateral direction or lateral acceleration since the passengercompartment is inward from the sensor housing relative to the side ofthe vehicle in the illustrated embodiment) resulting from a crash intothe side of the vehicle, will cause the sensing mass 141 to move orpivot outward toward the impacting object thereby releasing its hold onthe biasing spring 142.

[0072]FIG. 3 shows a fragmentary view of a sensing mass 341 and anattached lever arm 356 extending from a D-shaft 358 prior to rotation ofthe sensing mass incident to a crash as adapted to the all-mechanicalsystem of Thuen, U.S. Pat. No. 4,580,810. This figure corresponds toFIG. 6 of the Thuen patent and shows the improved sensing mass design.FIG. 4 shows the same view as FIG. 3 with the sensing mass rotated,under the torque from spring 360 acting on ball 470, into the actuatingposition where it has released the firing pin to initiate deployment ofthe airbag. FIG. 4 corresponds to FIG. 7 in the '810 patent. FIG. 5 is aview taken along line 5-5 of FIG. 4 and shows the shape of the sensingmass 341. Sensing mass 341 is retained in sensor housing 338, by cover339, and rotates with D-shaft 358. This rotation is facilitated bypivots 371, which form part of the D-shaft, and pivot plates 370. Inthis manner, the sensing mass 341 is hinged to the sensor housing 338permitting only rotational motion and rendering the sensor insensitiveto the effects of cross-axis accelerations. In this embodiment, sensingmass 341, lever arm 356, ball 470, pin 469 and the D-shaft 358 are allmade as one part that reduces the cost of the assembly. Naturally, theycould be made as separate parts and assembled. When D-shaft 358 rotatesthrough a sufficient angle, it releases firing pin 336 in the samemanner as shown in FIGS. 8 and 9 of the '810 patent. The motion of thesensing mass 341 is undamped since the clearance between the sensingmass 341 and sensor housing 338 is sufficiently large so as to minimizethe flow resistance of the air as the mass rotates. Naturally, inanother implementation, the mass could be redesigned to have its motiondamped by the flow of a gas in the manner shown in FIGS. 1 and 2 above.Also, two sensor systems of the type disclosed in FIGS. 3-5 can be usedin the all-mechanical system in a similar way as shown in the '810patent.

[0073] The all-mechanical system as depicted in FIGS. 3-5 requires thata special inflator be designed to accommodate the sensor within itshousing. There has already been a substantial investment in tooling andproduction facilities for electrically actuated inflators by severalinflator manufacturers. Also, substantial reliability statistics havebeen accumulated on these inflator designs through the hundreds ofmillions of miles that airbag equipped vehicles have traveled. It isdesirable to build on this base with new systems that can be done usingthe sensor designs of this invention as depicted in FIGS. 6 and 7. Thissensor design is adapted to be attached to a standard electricalinflator design where a stab primer 691 is used in place of theelectrically actuated squib normally used.

[0074] The sensor-initiator is shown generally as 600 in FIG. 6. In asimilar manner as described above, sensing mass 641 rotates in sensorhousing 630 during a crash against the force provided by a cantileveredbiasing spring 662 until a D-shaft 658 has rotated sufficiently torelease a firing pin 636. Once released, firing pin 636 is propelled byfiring pin spring 635 and impacts primer 691 to initiate deployment ofthe airbag. A washer containing an orifice 692 is provided in the top ofprimer 691 to minimize the leakage of inflator gases from the inflator690 while the propellant is burning (FIG. 7). In this manner, the sensordoes not have to be constructed of strong materials as discussed in theabove referenced patent.

[0075] In one configuration of a self-contained system, the sensorassembly and the airbag and inflator assembly are kept separate untilmounted onto the vehicle. In this case, the sensor is mounted using anappropriate apparatus (not shown) to the steering wheel after the wheelis mounted to the vehicle. Then, the airbag module is assembled to thesteering wheel. In this case, the sensor is armed after it has beeninstalled onto the vehicle through the use of arming screw 670. Theinflator is only brought into contact with the sensor after the sensorhas been mounted onto the vehicle, thus minimizing the chance of aninadvertent actuation prior to installation. To arm the sensor, armingscrew 670 is rotated after the sensor is mounted onto the steering wheelcausing it to move downward in its housing 674. This removes theretaining cylinder 673 from blocking the motion of locking ball 675 thatremoves a lock on the firing pin. As long as ball 675 remains lockingthe firing pin 636, rotation of the mass 641 will not release the firingpin and the sensor is unarmed. Additional apparatus, not shown, can beused to prevent the assembly and disassembly of the sensor from thesteering wheel unless the arming screw 670 is in the unarmed position.Also, interference between the head 680 of the arming screw 670 and thesurface 693 of the inflator 690 prevents assembly of the inflator andairbag module to the steering wheel until the sensor has been armed.Thus, in this very simple manner, an inexpensive all-mechanical airbagsystem can be made using standard inflator designs with minormodifications.

[0076] In FIGS. 1 and 2, the stab primer was shown as part of theinflator assembly, i.e., contained within the housing of the inflatorassembly defined by housing portions 121,129. On the other hand, in FIG.8. a cross section view of a through bulkhead initiation system adaptedto a mechanical self-contained airbag system is illustrated. In thiscase, the stab primer 822 is instead part of a sensor assembly 840,i.e., arranged in the sensor housing on the bottom cover thereof ifpresent, and when the stab primer 822 is initiated by a firing pin 842formed in conjunction with a cantilevered, biasing spring (as in theembodiment shown in FIGS. 1 and 2), it creates a shock on one side of aninflator housing wall 821 which is transmitted through the wall andinteracts with a shock sensitive pyrotechnic mix 829 which has beenplaced into a cavity 805 in the igniter mix. Inflator housing wall 821is alongside the bottom cover of the sensor housing, but in thealternative, the inflator housing wall may be the same as the bottomcover of the sensor housing. This through-bulkhead initiation system andthe particular pyrotechnic mix formulation is well known to ordinanceengineers where it has been applied to military devices. Such a systemhas not been used, however, in airbag systems. In this manner, a hole isnot opened between the sensor assembly and the inflator assembly and thegas is prevented from leaking into the sensor assembly.

[0077] In FIG. 9, a perspective view of a mechanical self-containedairbag system using a crush sensing arming system designated generallyas 950 is shown in the state before a crash occurs. In this embodiment,the sensor is armed when the vehicle door skin, or side skin, is crushedto where it impacts a curved impact plate, not shown, which then impactsa sensor can 970 surrounding the sensor assembly and displaces an outercover 951 thereof relative to a sensor housing 901. Sensor can 970 has atubular wall arranged partially alongside a housing section of theinflator assembly to thereby define a closed space between the outercover 951 and an outer surface of the inflator assembly in which thesensor assembly is positioned. The sensor crush-sensing outer cover 951has a slight arcuate shape so that it oil-cans downward pressing onlever 971 through a hemi-spherical pusher member 979. Lever 971 ishingedly mounted at one end thereof to enable it to rotate about itsattachment point 972 to the sensor housing 901 and causes lever 973 toalso rotate about its pivot point 974 on the sensor housing 901 byvirtue of hinge 978. An end 975 of lever 973 extends through an aperture904 in a wall of the sensor housing 901 and serves to restrain thesensing mass 941 from any movement (FIG. 10). The rotation of lever 973causes the end 975 of lever 973 to pull out of the sensor housing 901where it was detenting the sensing mass 941 and preventing the sensingmass 941 from rotating to the degree necessary to release a firing pinspring 942. The sensing mass 941 is then free to move and release thefiring pin spring 942 causing the firing pin spring 942 to ignite thestab primer in the inflator assembly, either by contact therewith or bypressure against the inflator assembly housing (see above) causinginflation of the airbag (FIG. 11A). Thus, until the sensor experiences acrushing force from the crash, the airbag system cannot deploy. Thesensing mass 941, firing pin spring 942, inflator assembly and airbagmay have the same structure as described above with reference to FIGS. 1and 2. Other features of any of the disclosed embodiments notinconsistent with the embodiments shown in FIGS. 9-11 may also beincorporated therein.

[0078] Levers 971 and 973 are joined together by hinge 978 and can bemade from a single piece of material. In this case, the hinge would beformed either by a coining or stamping operation or by a millingoperation. Naturally, the two levers need not be joined together.

[0079] This provides a sensor system that requires the occurrence of twoenvironments that are always present in a crash, crush and velocitychange. The crush sensing outer cover 951 is designed to respond and armthe sensor when impacted from any reasonable direction by an impactplate (not shown) which is likely to occur in a crash. For manyvehicles, the crush may not reach the sensor at the time that deploymentis required. In the case where two systems are used on each side of thevehicle, for example, and an impact occurs at the A-pillar, the rearseat system may not experience crush in time. The arming system shown inFIG. 9 could still be used where the arming would occur when the systemis mounted onto the vehicle instead of when the crash occurs. In thiscase, the curved impact plate would not be necessary and the deflectionof the sensor cover would occur either during the mounting process or bya separate operation after the system is mounted.

[0080]FIG. 10 is a cross section view of the apparatus of FIG. 9 takenalong lines 10-10 showing the crush sensing outer cover 951 and leversystem after end 975 has moved out of aperture 904 as a result of crushof the vehicle but before the sensing mass 941 of the discriminatingsensor has begun to move. FIG. 11 is a similar view of the apparatus ofFIG. 10 but shows the sensing mass 941 of the discriminating sensorafter it has moved and released firing pin 942, triggering the inflationof the airbag.

[0081] The motion of the sensing mass 941 is damped by the requirementthat air must flow between the sensing mass and the housing in themanner described in more detail in the '253 patent referenced above.Naturally, other damping methods such as magnetic damping could also beused.

[0082] In the case of FIG. 9, the sensor is entirely surrounded by ametal can 970 that is formed by a drawing process. The sensor can 970 isattached to the inflator assembly; more particularly, the sensor can 970is attached to one or more housing sections thereof. The attachment ofthe sensor can 970 to the inflator assembly or housing section(s)thereof is achieved using structural adhesive 990 such as a urethane orepoxy compound. In this manner, the sensor is hermetically sealed.

[0083] The term hermetic seal as used herein means a seal which will notpermit the passage of any significant amount of moisture or othercontaminants into the interior of the self-contained airbag module andfurther will not permit the passage of gas into or out of the sensorhousing of sufficient quantity as to change the gas density by more thanabout 5% at any time over the life of the vehicle. Each vehiclemanufacturer has an accelerated life test that can be used along withappropriate sensor testing equipment to test the sensor seals accordingto this definition. Typical O-ring seals are not hermetic by thisdefinition however properly designed plastic and metal welded seals andepoxy and urethane seals are hermetic.

[0084]FIG. 12 is a perspective view of a side impact airbag systemillustrating the placement of the airbag vents in the door panel and theexhausting of the inflator gases into the vehicle door 1200 and alsoshowing the use of a pusher plate 1201 to adjust for the mismatchbetween the point of impact of an intruding vehicle (or other object)and the sensor of a self-contained side impact airbag system 1220. Thepusher plate 1201 is shown attached to the main structural door beam1202 in this illustration but other mounting systems are also possible.The airbag system 1220 is shown between the inner panel 1230 and theouter panel 1240 of the door 1200.

[0085] The pusher plate 1201 is dimensioned and installed in the door1200 so that during a side impact to any portion of the side of thevehicle which is likely to cause intrusion into the passengercompartment and contact an occupant, the pusher plate will remain in asubstantially undistorted form until it has impacted with the sensorcausing the sensor to begin deployment of the airbag. In thisimplementation, a non-sodium azide propellant, such as nitro-cellulose,is used and the gas is exhausted into the door though a pair oforifices. The airbag system 1220 may be any of those disclosed herein.

[0086] As shown in FIG. 12, the pusher plate 1201 may be circular.

[0087]FIG. 13 is a cross-sectional view of a self-contained side impactairbag system using an electromechanical sensor. An electromechanicalsensor is one in which the sensing is accomplished through the motion ofa sensing mass from a first at-rest position to a second activatingposition at which point an event happens which typically involves theclosing of a switch by mechanical or magnetic means. In the embodimentshown in FIG. 13, biasing spring contact 1301 is caused to engagecontact 1302 arranged on top cover 1350 when the sensor experiences acrash as described above, i.e., acceleration of the sensor housing 1310above a predetermined threshold value which results in movement of thesensing mass until the biasing contact 1301 contacts the other contact1302. Specifically, the biasing spring contact 1301 is positioned in aposition (e.g., bearing against sensing mass 1341 in sensor housing1310) so that it is moved during a crash along with movement of thesensing mass 1341 (in the upward direction in FIG. 13) to thereby bringthe biasing spring contact 1301 into contact with contact 1302. Anelectrical circuit is thereby completed causing ignition of the primeror squib and thereafter the igniter mix and propellant. As shown in FIG.13, the structure of the sensor housing 1310, inflator assembly 1312,mounting plate 1360 and sensing mass 1341 may be as described above inappropriate part.

[0088] The implementation of FIG. 13 is a preferred location for theself-contained airbag module of this invention. Naturally, some of theteachings of this invention can be practiced without necessitating aself-contained module. For some implementations, for example, it isdesirable to place the airbag module at some other location than thevehicle door. One such location, for example, is the vehicle seat. Forthis implementation, the crash sensor in general cannot be co-locatedwith the airbag module. Therefore, it can be mounted on the side of thevehicle or elsewhere as long as there is a sufficiently strong memberconnecting the crash sensor to the vehicle side such that there islittle or no plastic deformation between the sensor and the side of thevehicle. Thus, the sensor experiences essentially the same crash signalas experienced by the side of the vehicle. Through this technique, thesensor acts as if it were mounted on the side of the vehicle and yet thewiring does not have to go through the door and through the hinge pillarto the airbag module. In this way, the sensor can be mounted remote fromthe vehicle side and yet perform as if it were located on the vehicleside which is accomplished by using an extension of the sensor, whichcan be a structural member of the vehicle.

[0089]FIG. 14 is a cross-sectional view of a self-contained side impactairbag system using an electronic sensor that generates a signalrepresentative of the movement of a sensing mass. Unless otherwisestated or inconsistent with the following description of an airbagsystem with an electronic sensor, the airbag system with an electronicsensor may include the features of the airbag system described above andbelow. An electronic sensor is one in which the motion of the sensingmass is typically continuously monitored with the signal electronicallyamplified with the output fed into an electronic circuit which isusually a micro-processor. Electronic sensors typically useaccelerometers that usually make use of strain gage or piezo-electricelements shown here as 1401. The piezo-electric element generates asignal representative of the movement of the sensing mass. Modemaccelerometers are sometimes micro-machined silicon and combined withother elements on an electronic chip. In electromechanical sensors, themotion of the sensing mass is typically measured in millimeters and ismuch larger than the motion of the sensing mass in electronic sensorswhere the motion is frequently measured in microns or portions of amicron. The signal representative of the motion of the sensing mass isrecorded over time and an algorithm in the micro-processor may bedesigned to determine whether the movement over time of the sensing massresults in a calculated value which is in excess of the threshold valuebased on the signal. The sensing mass may constitute part of theaccelerometer, e.g., the sensing mass is a micro-machined accelerationsensing mass. In this case, the microprocessor determines whether themovement of the sensing mass over time results in an algorithmicdetermined value that is in excess of the threshold value based on thesignal.

[0090] In embodiments using an electronic sensor, the inflator mayinclude a primer which is part of an electronic circuit including theaccelerometer such that upon movement over time of the sensing massresults in a calculated value in excess of the threshold value, theelectronic circuit is completed thereby causing ignition of the primer.

[0091] When the term electrical as used herein it is meant to includeboth electromechanical and electronic systems.

[0092]FIG. 15 is a schematic of the electric circuit of anelectromechanical or electronic side impact airbag system. Theself-contained module implementation shown generally at 1500 contains asensor assembly 1540 and an airbag and inflator assembly 1510. Thesensor assembly 1540 contains a sensor 1541, a diagnostic module 1542,an energy storage capacitor 1543, and a pair of diodes 1515 to preventaccidental discharge of the capacitor if a wire becomes shorted. Themodule is electrically connected to a diagnostic monitoring circuit 1560by wire 1501 and to the vehicle battery 1570 by wire 1503. It is alsoconnected to the vehicle ground by wire 1502. The sensor, diagnostic andcapacitor power supplies are connected to the squib by wires 1505through 1507.

[0093] In a basic configuration, the diagnostic monitoring circuit 1560checks that there is sufficient voltage on the capacitor to initiate theinflator in the event of an accident, for example, and either of wires1501, 1502, 1503 or 1504 are severed. In this case, the diagnosticinternal to the self-contained module would not be necessary. In moresophisticated cases, the diagnostic module 1542 could check that thesquib resistance is within tolerance, that the sensor calibration iscorrect (through self testing) and that the arming sensor has notinadvertently closed. It could also be used to record that the armingsensor, discriminating sensor and airbag deployment all occurred in theproper sequence and record this and other information for futureinvestigative purposes. In the event of a malfunction, the diagnosticunit could send a signal to the monitoring circuitry that may be no morethan an indication that the capacitor was not at full charge.

[0094] A substantial improvement in the reliability of the system isachieved by placing the diagnostic module and backup power supply withinthe self contained airbag system particularly in the case of sideimpacts where the impact can take place at any location over a widearea. An impact into a narrow pole at the hinge pillar, for example,might be sufficient to sever the wire from the airbag module to thevehicle power source before the sensor has detected the accident.

[0095] Most of the advantages of placing the sensor, diagnostic andbackup power supply within the self contained module can of course beobtained if one or more of these components are placed in a secondmodule in close proximity to the self contained module. For the purposesof electromechanical or electronic self contained modules, therefore, asused herein, the terms “self contained module” or “self contained airbagsystem” will include those cases where one or more of the componentsincluding the sensor, diagnostic and backup power supply are separatefrom the airbag module but in close proximity to it. For example, in thecase of steering wheel mounted systems, the sensor and backup powersupply would be mounted on the steering wheel and in the case of sideimpact door mounted systems, they would be mounted within the door orseat. In conventional electrical or electronic systems, on the otherhand, the sensor, diagnostic module and backup power supply are mountedremote from the airbag module in a convenient location typicallycentrally in the passenger compartment such as on the tunnel, under theseat or in the instrument panel.

[0096] With the placement of the backup power supply in the selfcontained module, greater wiring freedom is permitted. For example, insome cases for steering wheel mounted systems, the power can be obtainedthrough the standard horn slip ring system eliminating the requirementof the ribbon coil now used on all conventional driver airbag systems.For side impact installations, the power to charge the backup powersupply could come from any convenient source such as the power window ordoor lock circuits. The very low resistance and thus high qualitycircuits and connectors now used in airbag systems are not requiredsince even an intermittent or high resistance power source would besufficient to charge the capacitor and the existence of the charge isdiagnosed as described above.

[0097] Herein, the terms capacitor, power supply and backup power supplyhave been used interchangeably. Also, other energy storage devices suchas a rechargeable battery could be used instead of a capacitor. For thepurposes of this disclosure and the appended claims, therefore, the wordcapacitor will be used to mean any device capable of storing electricalenergy for the purposes of supplying energy to initiate an inflator.Initiation of an inflator will mean any process by which the filling ofan airbag with gas is started. The inflator may be either purepyrotechnic, stored gas or hybrid or any other device which provides gasto inflate an airbag.

[0098]FIG. 16 is a side view showing the preferred mounting of two selfcontained airbag modules 1601 and 1602 on the side on a two doorvehicle. Module 1601 is mounted inside of a door, whereby the sensorhousing 101 of module 1601 is most proximate the exterior of thevehicle, while module 1602 is mounted between the inner and outer sidepanels at a location other than the door, in this case, to protect arear seated occupant. Each of the modules has its own sensor and, in thecase of electrical self-contained systems, its own capacitor powersupply and diagnostic circuit. Any of the airbag systems disclosedherein may be mounted either inside a door or between inner and outerside panels of the vehicle at a location other than the door and for nonself-contained systems, the sensor can be mounted anywhere providedthere is a sufficiently strong link to the vehicle side so that thesensor is accelerated at a magnitude similar to the vehicle side crushzone during the first few milliseconds of the crash. In view of themounting of module 1602 between inner and outer panels of the vehicle ata location other than the door, the inner and outer panels are thusfixed relative to the vehicle frame and the module 1602 is also thusfixed relative to the frame. By contrast, the module 1601 mounted insidethe door is moved whenever the door is opened or closed.

[0099] Although several preferred embodiments are illustrated anddescribed above, there are possible combinations using other geometries,materials and different dimensions for the components that can performthe same function. For example, the biasing spring need not be the sameas the biasing spring in the case of the implementation shown in FIG. 1and a magnet might be used in place of a biasing spring for several ofthe mechanical cases illustrated. Therefore, this invention is notlimited to the above embodiments and should be determined by thefollowing claims.

What is claimed is:
 1. A vehicle having a longitudinal axis between afront and rear of the vehicle such that a lateral direction is definedperpendicular to the longitudinal axis, comprising: a side impact crashsensor for detecting a lateral force or acceleration applied to a sideof the vehicle; transfer means interposed between the side of thevehicle and said sensor for transferring the lateral force applied tothe side of the vehicle to said sensor; and an occupant restraint deviceconnected to said sensor and arranged to deploy an occupant restraintbased on the force or acceleration detected by said sensor.
 2. Thevehicle of claim 1, wherein said transfer means are arranged to adjustfor mismatch between a point of impact of an object on the side of thevehicle and said sensor.
 3. The vehicle of claim 2, wherein saidtransfer means comprise a plate capable of remaining substantiallyundistorted in form upon application of the lateral force to the side ofthe vehicle.
 4. The vehicle of claim 3, further comprising a mainstructural beam, said plate being mounted to said main structural beam.5. The vehicle of claim 4, further comprising a door, said mainstructural beam being arranged in said door
 6. The vehicle of claim 3,wherein said plate is circular.
 7. The vehicle of claim 3, furthercomprising a door having an inner panel and an outer panel, said platebeing located between said inner panel and said outer panel.
 8. Thevehicle of claim 1, further comprising a main structural beam, saidtransfer means being mounted to said main structural beam.
 9. Thevehicle of claim 8, further comprising a door, said main structural beambeing arranged in said door
 10. The vehicle of claim 1, furthercomprising a door having an inner panel and an outer panel, saidtransfer means being arranged between said inner panel and said outerpanel.
 11. A vehicle having a longitudinal axis between a front and rearof the vehicle such that a lateral direction is defined perpendicular tothe longitudinal axis, comprising: a side impact crash sensor fordetecting a lateral force or acceleration applied to a side of thevehicle; mismatch adjustment means interposed between the side of thevehicle and said side for adjusting for mismatch between a point ofimpact of an object on the side of the vehicle and said sensor; and anoccupant restraint device connected to said sensor and arranged todeploy an occupant restraint based on the force or acceleration detectedby said sensor.
 12. The vehicle of claim 11, wherein said mismatchadjustment means are arranged to transfer the lateral force applied tothe side of the vehicle by the object to said sensor.
 13. The vehicle ofclaim 11, wherein said mismatch adjustment means is a plate capable ofremaining substantially undistorted in form upon application of thelateral force to the side of the vehicle.
 14. The vehicle of claim 13,further comprising a main structural beam, said plate being mounted tosaid main structural beam.
 15. The vehicle of claim 14, furthercomprising a door, said main structural beam being arranged in said door16. The vehicle of claim 13, wherein said plate is circular.
 17. Thevehicle of claim 13, further comprising a door having an inner panel andan outer panel, said plate being located between said inner panel andsaid outer panel.
 18. The vehicle of claim 11, further comprising a mainstructural beam, said mismatch adjustment means being mounted to saidmain structural beam.
 19. The vehicle of claim 18, further comprising adoor, said main structural beam being arranged in said door
 20. Thevehicle of claim 11, further comprising a door having an inner panel andan outer panel, said mismatch adjustment means being arranged betweensaid inner panel and said outer panel.
 21. A vehicle having alongitudinal axis between a front and rear of the vehicle such that alateral direction is defined perpendicular to the longitudinal axis,comprising: a side impact crash sensor for detecting a lateral force oracceleration applied to a side of the vehicle; a transfer deviceinterposed between the side of the vehicle and said sensor suitable fortransferring a lateral force applied to the side of the vehicle by anobject to said sensor; and an occupant restraint device connected tosaid sensor and arranged to deploy an occupant restraint based on theforce or acceleration detected by said sensor.
 22. The vehicle of claim21, wherein said transfer device is arranged to adjust for mismatchbetween a point of impact of an object on the side of the vehicle andsaid sensor.
 23. The vehicle of claim 22, wherein said transfer devicecomprises a plate capable of remaining substantially undistorted in formupon application of the lateral force to the side of the vehicle. 24.The vehicle of claim 23, further comprising a main structural beam, saidplate being mounted to said main structural door beam.
 25. The vehicleof claim 24, further comprising a door, said main structural beam beingarranged in said door
 26. The vehicle of claim 23, wherein said plate iscircular.
 27. The vehicle of claim 23, further comprising a door havingan inner panel and an outer panel, said plate being located between saidinner panel and said outer panel.
 28. The vehicle of claim 21, furthercomprising a main structural beam, said transfer device being mounted tosaid main structural beam.
 29. The vehicle of claim 28, furthercomprising a door, said main structural beam being arranged in said door30. The vehicle of claim 21, further comprising a door having an innerpanel and an outer panel, said transfer device being arranged betweensaid inner panel and said outer panel.